378 ANNUAL REPORT OF THE Off. Doc. 



This lack is very decidedly met by the manure treatment of plot 

 8. In this plot, tbe trees are making a luxuriant growth, both 

 in wood and foliage, and the yields have been increased by 390 

 bushels per acre annually, — a very satisfactory exchange for 12 

 tons of stable manure. Even this increase in yield, however, is 

 considerably less than those obtained on the plots receiving a nitro- 

 gen-carrying fertilizer. Under the latter treatment on three plots, 

 the average annual yield has been increased from 191 bushels on the 

 checks to 649 bushels on the fertilized plots, or an annual increase 

 of 457 bushels of apples per acre. This resulted from fertilizer 

 applications that actually cost less than $17, and the essentials of 

 which can be bought at retail for about |10 per acre. During the 

 past year, — the fourth year of the experiment, — as shown in Table 

 II, the yield on plots 2 and 3, compared with that of their adjacent 

 checks, was at the rate of 17 to 1, the yield on the checks being at 

 the rate of 54 bushels per acre, while that on the intervening nitro- 

 gen plots was 922 bushels. Surely it is not necessary to further 

 defend the thesis that proper fertilizatition may very profoundly af- 

 fect the yield of apjdes. 



Theie is no reasonable possibility of these results being due to 

 any other agent than the fertilizers. The trees are all of the same 

 variety and same age. They receive the same spraying, pruning, soil 

 handling and other care. The soil is practically level and very uni- 

 torm. The treatments are abundantly checked. In fruit, foliage, 

 growth and general health of trees, the benefits stop abruptly where 

 the fertilizers stop, and similar results are being obtained by the 

 owner in other parts of the orchard, on the same and other varieties, 

 with the combinations of fertilizers found effective in the experi- 

 ment. 



In regard to the relative values of the different fertilizer ele- 

 ments, it will be seen in Table II, that nitrogen is evidently the first 

 limiter. Thus, the phosphate and potash combination in plot 5 has 

 given an increase of 123 bushels per acre, while by the addition of 

 nitrogen to this combination, in the adjacent plot 6, we get an in- 

 crease of 480 bushels. In other words, the addition of nitrogen to 

 the treatment ordinarily advised for orchards, resulted here in 

 nearly quadrupling the benefit, in plot 3, where the phosphates are 

 omitted, it will also be noted that there is an annual deficit which 

 amounts to nearly SO bushels per acre. This doubtless indicates 

 that phosphorus is the second limiter and that the yield in plot 3 is 

 being reduced by lack of this element. Potash applications, on 

 the other hand, have been practically of no avail in this experiment. 

 This may be seen by comparing plots 2 and 6. The annual addition 

 of 150 pounds of actual K20 in the latter treatment has resulted 

 in a gain of only 3.7 bushels of apples. 



The above results were obtained without any aid from tillage 

 or cover-crops, the fertilizers being merely sowed over the surface 

 of unfilled soil, on which there was a light sod composed chiefly 

 of mixed grasses. Here the question may be raised as to whether 

 equal or superior benefits may not have been obtainable with some 

 form of cultural methods. This question is answered in Table IV: 



